They really do work. I’ve seen reviews and you’re always a bit skeptical. I did a 950mi roadtrip with these on & saw a 12-15% efficiency compared in wh/mi compared to the previous 3000 miles I have done on my car without. (1/4th of the trip was Interstate, and the rest was on backroads and highways, 80-90F outside with 69F inside on fan speed 4-5 2026 Model Y Premium AWD). Very impressed !